Induction of ovulation and spawning of cultured pejerrey Odontesthes bonariensis by implantation of a sustained-release GnRH-a pellet

MIRANDA LA; SOMOZA GM

AQUACULTURE RESEARCH

Wiley-Blackwell

Lugar: London; Año: 2009 vol. 41 p. 129 - 134

1355-557X

The aim of this study was to induce and synchronize spawning of pejerrey Odontesthes bonariensis (Valenciennes, 1835), using gonadotropin releasing hormone agonist (GnRHa) implants. In the ¢rst experiment, the ovarian condition was assessed by ovarian biopsies and the measurement of the genital pore width (GPW). Females having the leading clutch of oocytes with a diameter of around 800^900 mm and a GPW between 4.5 and 5.5mm were treated with GnRHa implants. Eighty per cent of females spawned between 2 and 9 days after treatment, 12 days earlier than 20% of the ¢sh in the control group that presented signs of spawning activity. In order to avoid any possible ovarian injury and/or stress by the catheterizationprocedure, ina second experiment, females were selected only by visual inspection of the abdomen and GPW measurement. As in experiment 1,80%of females spawned between 2 and 8 days after treatment, 8 days earlier than 30% of the ¢sh that spawned in the control group. In both experiments, fertilization and hatching success were similar between control and GnRHa-treated groups. These results clearly demonstrated that GnRHa implantation can advance and synchronize ovulation and spawning in pejerrey without a¡ecting egg quality.